“An” is one of the two indefinite articles that exist in the English language (the other one is “a”).[1] While there is no difference in meaning between “an” and “a,” there are rules concerning when to use “a” and when to use “an.” Taking time to learn about the different rules surrounding these indefinite articles will help make you sound well-educated when speaking, and will make your writing more enjoyable to read.

Steps

Part 1

Understanding When to Use the Word “An”

1

Understand the role of indefinite articles in the English language. In the English language there are only two indefinite articles: “a” and “an.” The two words have the exact same meaning. If you say “I want to read an book” or “I want to read a book,” the meaning is exactly the same. However, the first one is not grammatically correct.[2] There are many situations which might require the use of an indefinite article. For example:

If you are referring to something/someone for the first time (such as “I’ve found a good job” or “She has a daughter.”)

When you are naming someone as a part of a specific group (“Jenny is a doctor” or “Robert is an engineer.”)

When referring to something non-specific (“I can come over on a Thursday.”)

When talking about an example of something (“The elephant has a long trunk” or “That is an enormous ball.”)

When talking about a singular object (“I would like an egg” or “I need a pound of flour.”)[3]

2

Memorize the rule. If a word starts with a vowel sound then you should use the indefinite article “an” before it. On the other hand, if a word starts with a consonant sound you should use the indefinite article “a” before it.[4]

Generally, this will mean that if the word starts with a vowel you should use “an,” but it is important to remember that this is not true all of the time. This is because the rule is focused on the sound, and not the actual letter that the word starts with.

For example, although “one-day event” begins with a vowel (“O”) you would not say, “an one-day event.” In this case, the first word makes a consonant sound, and you would say, “a one-day event.” If you think about it, the “O” in one does not make an “O” sound, but it actually makes a “W” sound because the word “one” is actually pronounced more like, “won.”

In the alphabet, there are 6 vowels. These include: “A,” “E,” “I,” “O,” “U,” and sometimes “Y.” “Y” is only used as a vowel in some words such as “gym” and “baby,” but acts as a consonant in other words such as “young” and “beyond.” When you pronounce a vowel, the air flows freely through your mouth without having to be interrupted by your tongue or throat to pronounce it.

All the other letters in the alphabet are considered consonants, which means that you have to interrupt the flow of air through your mouth when you pronounce it. For example, you have to use your tongue to say the “L” in “limit,” you use your tongue to stop the flow of air when you pronounce the “H” in “hurt.”[5]

3

Say the word out loud. If you are a native English speaker, saying the phrase out loud can help you decide whether you should use “an” or “a.” Usually, when you say it out loud, it will sound strange to you if you have chosen the wrong one.

For example, if you aren’t sure whether to say “a apple” or “an apple” say them both out loud. You will probably realize that “a apple” sounds strange to you, and it may even feel a bit weird to say it that way. Then it becomes clear to you that “an apple” is the right choice.

Even if you are not a native speaker of English, saying the word out loud can be helpful in figuring out whether the word begins with a vowel sound. If the beginning of the word flows freely through your mouth without the need to use your tongue or throat to stop the air, then it is probably a vowel sound. For example, if you say “owl” out loud you will see that the “ow” sound flows very freely and is not stopped at any point.

Part 2

Remembering Exceptions

1

Don’t forget that acronyms work in the same way. Many people think that acronyms are an exception to the rule, but they actually work in exactly the same way. If the acronym starts with a vowel sound when you sound it out, then you should use “an.” If it uses a consonant sound you should use “a.”[6]

For example, you would say “an FBI agent” because the “F” in “FBI” makes a vowel sound (“eff”). On the other hand, you would not say “an CT scan” because the “C” in “CT” does not make a vowel sound. Instead, you would say “a CT scan.”

2

Remember that when a letter begins with “h” it may require “an.” Words that begin with “H” can be confusing when you’re trying to decide whether to use “a” or “an.” This is when it becomes important to remember that you are looking for a vowel ‘’’sound’’’ not just a letter that is a vowel. In many American English words, the “H” is silent making the word begin with a vowel sound.[7]

For example, in “hour,” “honor,” “herb,” and “heir” the “H” is always silent and the words begin with vowel sounds. Thus, you would say, “an hour,” “an honor,” “an herb,” and “an heir.”

For words like “horse,” “human,” and “humble person” the “H” is not silent so the word makes a consonant sound. Thus, you would say “a horse,” “a human,” and “a humble person.”

3

Remember that “U” doesn’t always make a “U” sound. Often, if a word begins with a “U” it doesn’t make a vowel sound so you need to use “a” instead of “an.” This is tricky because “U” is a vowel, but often makes a “Y” sound when used at the beginning of a word.[8]

For example, in the word “University” the “U” is a long “U” and sounds like “yew,” which is a consonant sound. Therefore, you would say “a University” not “an University.”

On the other hand the “U” in “Umbrella” really does make a “U” sound, so you would say “an umbrella” not “a umbrella.”

The decision to use "an" is always based on the way the letters are pronounced. FRC is pronounced ef-ar-see. It sounds like a vowel. Since "an" is used before vowel sounds, it makes the most sense to say "an FRC team."

In the case of the word, "one" you would use "a." This is because, although the word, "one" starts with a vowel, it does not make a vowel sound. When you say the word, "one" it sounds more like, "won".

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Tips

Sometimes British and American English differ in their pronunciation. The above rules are for American English.

If you are a non-native English speaker, don’t worry about it too much if you misuse “a” and “an” sometimes. Native English speakers also sometimes misuse these indefinite articles, and everyone will be able to understand what you mean.